(1) Field of the Invention
The invention relates to connectors and is directed more particularly to removable balanced transmission line connectors.
(2) Description of the Prior Art
In telecommunications and professional audio, a balanced line format is used for good rejection of external noise. A balanced line or balanced signal pair refers to a transmission line consisting of two conductors of the same type, each of which have equal impedances along their lengths and equal impedances to ground and to other circuits. Circuits driving balanced lines must themselves be balanced to maintain the benefits of balance. This may be achieved by transformer coupling using a balun transformer.
For reliability, electrical connections between circuit boards or between circuit board components are generally soldered. Typically, a printed circuit board is mechanically supported by a dielectric base plate. The printed circuit board metallization provides electrical seats for the circuit elements.
The circuit board metallization is designed to enable an electrical connection to the metal traces that form a balanced transmission line on each balun board tongue, or contact post. The electrical connection is made by soldering the metal traces on the balun board contact post to the partition element electrical seats on the printed circuit board.
This method is satisfactory when the likelihood of a failure of one component or board is extremely small. In complex systems, wherein a large number of boards are interconnected, a failure of one of the boards will likely require nearly complete disassembly of the system in order to replace the failed board.
As an example, a variety of active circuits can be incorporated into individual balun boards that provide the electrical interface between partition elements and system electronics. Some balun boards can incorporate power amplifiers that will enable transmitters. Other boards can incorporate low noise receivers that will enable high dynamic range signals acquisition systems. Boards incorporating other active circuits can enable radio frequency generators and sensors for a variety of specialized applications.
The large numbers of active circuits can open the possibility to occasional component failure. When a failure does occur, it will particularly advantageous to be able to exchange one or more failed boards without disassembling the entire interface assembly. Additionally, the ability to exchange various components can provide greater design flexibility.
There is a need for a connector that allows for independent removal and replacement of each such interface board without disassembly of the entire interface. Further, the connector needs to provide a mechanically rigid connection and an electrically sound interface coupling.